On 4/16/24 9:59 PM, E Shattow wrote:
On Tue, Apr 9, 2024 at 11:44 PM Bo Gan <ganbo...@gmail.com> wrote:

On 4/9/24 6:55 PM, E Shattow wrote:
Original speed class SD cards fail with this change "unable to change mode".


The BUS_ROOT clock will have to be switched to PLL2 anyway in U-Boot proper or
in Linux, because it's the parent or grandparent clock for *lots* of devices,
including PCIe, i2c, spi, qspi... If there's an issue with this change, then
I suspect there's something wrong with the dw_mmc driver.

Bo

I've bisected and can confirm this change is what breaks original
speed SD function on Milk-V Mars CM Lite (DFRobot mini router
carrier). Class 10 speed SD media does not seem to be affected.
Reverting the change allows the original speed SD media access to
function again. SD access is functional in Linux with and without the
change.

How to troubleshoot this?

Thanks,

E


If without the change (reverted), can you read/write the same SD media in U-boot
proper? (U-boot proper will switch BUS_ROOT to PLL2). One potential problem I
could think of is perhaps the SPL built is without SPL_PINCTRL_STARFIVE/JH7110
or the u-boot dts is missing the pinctrl that properly sets drive-strength and
other properties of the mmc0/1 pins. What dtb are you using? I tested this with
visionfive2 and it's working fine. Can you share the tree/config you used to
built for Milk-V Mars CM Lite? I don't see the corresponding dts being checked-
in to u-boot tree, so it helps if you can share the code. Thanks!

Bo

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